The invention relates to a method of making deformation test samples of metallic mechanically rigid single crystals for example for use as sample rods for testing mechanical stress, compression or bending strength of a material in material research.
In material research processes occurring in the interior of metals are preferably examined on single crystals because of the complexity of those processes. The single crystals are produced mainly in accordance with two different manufacturing methods, the method according to Czorchralski and the method according to Bridgeman-Stockbarger. In both cases cylindrical single crystals are obtained which however, cannot be used directly as deformation samples. The Czorchralski crystal has a varying diameter over its length caused by the particular manufacturing method, whereas the Bridgeman-Stockbarger crystal has a sufficiently constant diameter. Since single crystals are very sensitive to deformation, they are destroyed by the slightest bending during handling. For this reason, they cannot be formed to the desired shape. Not even working of the surface of single crystals by forming on a lathe, cutting or drilling or grinding is possible.
It is the object of the present invention to provide a method whereby deformation samples of single crystals such as sample rods can be shaped without being destroyed.